A push-push oscillator is an electronic device generally comprising two symmetrical balanced branches with the same fundamental frequency and opposite phase of oscillation. A push-push oscillator is formed by combining two balanced branches in such a way that the fundamental frequency signals are cancelled out while their second harmonic components, respectively at twice the fundamental frequency, are constructively summed and delivered to a load. A push-push oscillator may be used to provide signals having the second harmonic frequency without the need of an additional frequency multiplier. To get signals having the fundamental frequency and the second harmonic frequency, special techniques have to be applied. A known push-push oscillator with dual full-differential outputs is e.g. described in US 2007/0182502 A1.